For many years the B2 Bomber was used as an enclosure tool, particularly as part of tenuki joseki. However, that approach has been rejected. Now it is more often used as an overwhelmingly powerful shape that can decisively alter the course of a fight.
Before proceeding, please note that the following discourse is only for advanced Go players. Unless you've reached zero-dan (alias zeri-dan),
don't try to understand it. Most importantly is that you do not attempt to use this shape unless you understand its dynamics.
The following illustration shows its strength in action as an offensive shape:
Notice how weak the white stone is. In fact, it is so weak that it can be practically considered dead. This is just one example of the B2's power. Many times a play that prevents its formation is large.
Here the white stone is decimating Black's entire position. Notice the major difference between this and the earlier diagram. Before, the white stone was weak; here, it is stupendously powerful!
For another thing, note that the B2 Bomber has 10 liberties (no, this is not a lie. Count yourself and you'll see the astonishing truth -- 10!). This number, the 10, which in Jewish mysticism is full of cosmic power, makes it very difficult to capture a B2. Indeed, as statistical analysis done by a Korean-Indian-Russian team over three years shows, 10 is an unparalleled number in capturing races; the average tends to be near 5 or 6.
The B2 Bomber certainly is a powerful shape, and it 'certainly' never fails to amaze.
Finally, though we have already established the B2 as being "uber," there is one matter that is of note. As trestles, a KGS 2d, teaches, one should "ignore all proverbs." Amazingly enough, there are little to no proverbs about the B2! What that means is that trestle's postulate applies to the B2.
Clearly the creation of a B2 Bomber is game deciding. If you can understand its strength, the folk-saying goes, then you are a 5d (though, honestly, you could be just a 3d). Indeed, one can only imagine how different games would go if more people devoted a turn or two to forming a B2 Bomber.
For instance:
This position is a common enclosure shape. Later in the game, it will usually evolve into something like
Here, even a 5k can miss what's happening -- a B2 Bomber is under formation! One more move and it will be almost unstoppable. White must strike now. The entire balance of the game is at risk; no mistakes can be made at this point.
Compare the next two diagrams:
Both take the corner enclosure and add a stone, whether it be white or black. The primary difference between the diagrams, besides for the obvious points, lies in a principle discovered by a Korean pro:
Yes! As strange as it may seem at first, the B2 Bomber, when formed, is an example of Differential Influence!
(Upon rereading this, I came to realize that SL does not have any adequate pages on Differential Influence. Hopefully, one will be made or I will be forced to explain this high-dan concept in this lowly page about the B2 Bomber!)
Onwards to another point:
This is a position from a recent pro game. The first thing that one may notice is that Black has moved an extra time. That is because White naturally panicked after seeing Black's formation in the center and decided to pass. White did recover his stamina and managed to continue play after downing a cup of water. (As a side note, please not that the pro did not drink alchohol. Though the situation is scary, alchohol is not needed to deal with B2 Bombers. A B2 Bomber is not a good reason to become a drunkard (unless it is flying above your head and you see the bombs falling).)
The second thing noticable is that Black has a surplus of power in the center. Though Black has neglected the corners, the rest of the game will be a hard fight for White, as groups are chased to the waiting B2 Bomber that is hovering in the middle.
And indeed, 104 moves later, after a toughly fought ko, White did resign.
Modern thought on such play is that instead of passing, White should have dynamically attacked the B2 Bomber by playing in the center. This ties into Differential Influence:
There is a proverb, saying, A Bomber in play adds 4 to your kyus. This example shows the only possible way for White to reach Black's level of play.
Notice that Black still has the upper hand. The stone occupies tengen, which is the highest position on the board! This "small" difference in position is so critical that some have pushed for banning black from opening at tengen. Of course, such an idea is absurd. The B2 Bomber, despite apperances to the contrary, is stoppable.
The most basic idea for striking at a B2 Bomber is
[1]Do not panic!
The B2 is frightening, no one can deny that. But if you let it get to you, you've already lost half the battle. A positive mindset will do wonders, especially in such a difficult position.
(Though it is true that you made a huge blunder in letting the B2 come into existence. You should certainly be irked at yourself for that -- but do not let it influence your playing.)
Understanding the second idea is easier if we look at the following diagram:
Notice that White has played precisily at the tip of Black's formation -- thusly diffusing all its influence in that direction. This is a key idea: for all its benefits, the B2 is not a useful territorial shape. Instead, it is influential -- and in any fight, you should seek to ruin its influence.
Black is not going to let White push him around. He knows how strong his shape is, and he's going to fight the position out. This is a very violent reply, and one that is judged optimal. Anything else is a compromise and can lead to disaster for black.
All of this, however, is discussing the attacking of a B2 when it is placed in tengen as a ferocious opening strategy. What if the B2 appears elsewhere in the game?
This is a very realistic depicition of how a B2 could come into play. Here, black faces a major dilema, namely how to deal with the amazing threat.
I'll admit that my puny brains can not handle such a problem. As shown earlier, often B2 Bombers are part of complex 4p-strategy. I am not 4p, so I know not what to do :(.
A possible solution is to use ground to air missiles, or perhaps even air to air missiles to take the bomber out before it does any harm, as with the contra strategy. One problem with this solution is that your opponent may object to you carrying missiles.
Obviously, the answer to that is another missile.
This is what is left after one strategic missile is launched. The difference is plain to all -- the B2 Bomber is gone, and Black is free to expand into the lower-middle. If only all problems in life were so easily solved.
BenjaminGeiger: The inevitable result of air-to-air missiles:
(Sebastian:) The B2 Bomber also is predestined to make two eyes. Simply mirror it like this. This shape is called the B2B Bomber.
(Lynx:) Fantastic! I never approached the B2 Bomber on that angle! On other pages you state that you a kyu. Please do not mock us with such lies. Once you spout such wisdom at us, any claim of being a kyu is immediately destroyed.
Bildstein: Indeed, with such stunning insight, Sebastian is clearly giving away that he is at least of 4p strength. This leads me to beleive that Sebastian may indeed be Tartrate. Perhaps he deserves an entry in TartrateGossip?
Kyu players often have trouble make effective use of the B2 in play, because they often lack a deep enough understanding of the difference between light and thin, and heavy and thick. As a sort of stepping stone to the effective use of the B2, kyu players can try this, admittedly thinner, cousin of the B2.
It has some interesting qualities. For example, it is very difficult to stop the creation of the "thinner B2". Consider the above diagram after White has played the three marked stones with her first three moves. It is very difficult for Black to stop her, and if he tries, he ends up with his stones too close to White's thickness.
Lynx: Also note that Black would find it quite difficult to play inside the B2 Bomber and escape. 'Minor' facts like that are essential to fully appreciating a shape's strength.
Thad: Actually this is a much better variant of the B2Bomber for kyu players. Composed of a ponnuki and two semiponnuki.
However, I wonder if the B2Bomber is solely a high dan shape. I see it being employed quite often by low level kyus. Virtual beginners employ it quite often. Perhaps there is an intuitive power to this shape that makes it powerfull for all levels of play.
ThaddeusOlczyk: As an added note about the B2:
Some have claimed that this shape is a joke. Doubtlessly, they are trying to delude their opponents into poor play by tricking them into not using this excellent shape. However, it is an effective shape, and it is used quite often in advanced play.
For instance: http://kgs.kiseido.com/en_US/gameArchives.jsp?user=horse8161&oldAccounts=y .
On Nov 22, 2004 6:17 AM against matsumoto.
Black does eventually lose. It is a shame that the advantage gained was squandered. In fact, now that I think about it, tears come to my eye. Such is life, no? Black had a huge advantage, the indominatable B2. And somehow, Black loses.
There is a deeper meaning to that game. The B2, with its mystical 10 liberties, is full of spiritual power. We can only watch in silence as it teaches us all how to be better people.
Additional shapes that are similar:
ThaddeusOlczyk:The B2 is nothing compared to TheEnterprise.
The opposite in Karma relationships to the B2Bomber is the BloodyL
I think the deathstar formation should not be ignored